In general, a vehicle is equipped with a sensor for preventing fog from forming on the vehicle's window. The sensor is connected to an air conditioning system of the vehicle to automatically remove fog formed on the vehicle's window, thereby supporting safe driving.
Various apparatuses for preventing fog from forming on a vehicle window have been developed both at home and abroad. An example of such apparatuses is disclosed in U.S. Pat. No. 6,422,062 entitled “an integrated glass fog sensor unit” by Delphi Corp. In the conventional technique, the integrated glass fog sensor unit includes a glass surface temperature sensor, an ambient air temperature sensor, and a relative humidity sensor, and measures humidity and a temperature at the same location by locating the relative humidity sensor adjacent to the ambient air temperature sensor to obtain an exact dew point temperature.